H∞ loop-shaping control of an electric power steering system

In this paper H_infin loop-shaping control is employed to improve robust stability and performance of an electric power steering system (EPS). EPS systems employing an electric motor provide the assist torque on the steering mechanism to enhance steering feeling of driver during steering process. A loop shaping procedure is introduced to minimize the effects of disturbances on the output and a H_infin robust controller is used to ensure robust stability and refined performance of the system. The controller is justified via simulation on both nominal and perturbed model of system.